I don't recall if it was the full-size or compact I rented at the range a day or two ago, but I was quite impressed with it, except for one thing... It may be due to the fact that it was a rental, but the mag release is right where my finger sits, and it was very "sensitive". As in, the mag dropped out on more than one occasion, simply because my finger bumped it the wrong way while firing.
I used to carry a full size 40 DAO at work. If you can, avoid the DAO at all costs - super heavy, super long trigger pull.
Other than that, it's a big, nearly indestructible, very accurate gun. The grip is a bit too vertical for my taste, but I got used to it. I'd buy a Glock before an HK only because they fit me better. The HK is probably a superior gun.